The present invention relates to fluidized patient support systems and more particularly to the rolling undercarriage for same.
A fluidized patient support system typically weighs in the vicinity of 1,800 to 2,000 pounds when supporting a patient. An example of such fluidized patient support system is disclosed in U.S. Pat. No. 4,942,645 to Hargest et al, which is hereby incorporated herein by this reference. Other examples of fluidized patient support systems are disclosed in U.S. Pat. No. 3,428,973 to Hargest et al. U.S. Pat. No. 3,866,606 to Hargest, U.S. Pat. No. 4,483,029 to Paul, U.S. Pat. Nos. 4,564,965, 4,637,083, and 4,672,699 to Goodwin, the disclosures of each of the foregoing being hereby incorporated herein by this reference. Such systems must be mobile so that they can be moved to different locations within the health care facility as well as to permit their return periodically to a maintenance facility located off-site from the health care facility. Often such fluidized patient support systems must be moved while a patient is occupying the system. Because of the large amount of weight, such systems have relied upon heavy duty axles and wheels to render them mobile. In addition, heavy duty casters have been provided to render such systems mobile.
However, the surfaces over which such casters are rolled are not always level or even. Bumps and depressions are encountered. The traversal of such bumps and depressions produces significant shock loads upon the casters and can damage same. Moreover, such shocks can be felt by the patient occupying the fluidized system, and the potential danger and discomfort posed by such shocks further limits the instances in which such fluidized systems can be moved while a patient occupies same.